Meet The ‘Halloween Genes’: Spook, Shadow, And Shade

Nicole Wetsman

Scientists who study Drosophila, the humble fruit fly, like to have some fun when naming newly identified genes and proteins. There’s the Sonic Hedgehog protein (which looks spiky under a microscope), the Ken and Barbie genes (when they’re mutated, fruit flies don’t develop external genitalia), and the hangover gene (which is key for alcohol tolerance).

Nobel Prize-winners aren’t an exception to this practice: Christiane Nüsslein-Volhard and Eric Wieschaus won the 1995 Nobel Prize in Physiology or Medicine for their work on the genes responsible for fruit fly development, and over the course of their research, they identified the genes responsible for turning the spherical fruit fly embryo into a segmented, recognisable body. They named one cluster, which were lethal if they were mutated, the Halloween genes.

The family includes genes named shadow, spook, and shade. They encode enzymes called cytochrome P450—which humans have, as well, and are involved in controlling steroid hormones.

In fruit flies, the enzymes help synthesise the hormones involved in molting and exoskeleton formation. Disruption wrecks havoc on fruit fly development, causing devastating deformities. Mutations to the gene disembodied, for example, cause the fruit fly to have no distinction between the head and body. In haunted mutations, only the head forms, and not the body. These genes, and genes that have the same function, have also been found in the salmon louse and the mighty tardigrade.

Researchers conducting new studies of Drosophila development have kept their monikers on theme: Two proteins that control the expression of neverland and spookier were named Ouija board and séance—the latter of which was first described by a research team this February.

Kirst King-Jones, an associate professor at the University of Alberta, worked on séance. Originally, he said, his collaborator—who’d previously identified Ouija board—didn’t give the new protein a Halloween-themed name. “But we met up at a conference, and I said we had to call it séance, because that’s what Ouija boards do,” King-Jones says. “We think it’s fun to keep the tradition for this entire network.”

In another Halloween connection, King-Jones’ current research is considering this network of genes as part of his research on porphyria—sometimes called vampire disease. Porphyrias are rare blood disorders where the body doesn’t properly produce hemoglobin, which carries oxygen to cells. King-Jones is looking at mutations that affect heme, one of the components of hemoglobin. Heme happens to be critical to the production of the same hormones that the Halloween genes help make.

Studying these genes in Drosophila helps scientists build an understanding of the systems that can then apply to humans.“This is really basic research on how steroid hormones are regulated,” King-Jones says. “Regardless of the organism they’re in, humans or flies, they’re powerful regulators.”

So, full-grown human or tiny fruit fly, we all have similar chemicals working in similar ways to control everything that happens in our bodies. Now that’s spooky.